In a printer wherein a single motor is used to drive a carriage from left to right in the printing mode and from right to left during carriage return, some means must be provided for stopping the motor when the carriage has reached its end of print position during the print mode and its home position during carriage return.
To accomplish the foregoing highly complex electromechanisms have been used. These mechanisms have used one or more A.C. motors requiring sophisticated A.C. motor switching circuitry as well as complex gearing, clutch and cable arrangements.
The present invention contemplates a simple circuit and logic arrangement in conjunction with an inexpensive D.C. permanent magnet bi-directional motor which is capable of energizing the motor to run in either direction. When it is desired to stop the motor, logic circuit means are provided to apply a reverse or braking current to the motor. When the braking current has caused the motor to reach a virtual stop condition, further circuit means are provided to disable the motor without removing the condition which provides the braking current. This permits the braking current to be automatically applied as motor drive current when the circuitry again enables the motor.